////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2011-2021 The Octave Project Developers
//
// See the file COPYRIGHT.md in the top-level directory of this
// distribution or <https://octave.org/copyright/>.
//
// This file is part of Octave.
//
// Octave is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Octave is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Octave; see the file COPYING.  If not, see
// <https://www.gnu.org/licenses/>.
//
////////////////////////////////////////////////////////////////////////

#if ! defined (octave_octave_qobject_h)
#define octave_octave_qobject_h 1

#include <memory>

#include <QApplication>
#include <QList>
#include <QObject>
#include <QString>
#include <QStringList>

#include "interpreter-qobject.h"
#include "resource-manager.h"
#include "shortcut-manager.h"

namespace octave
{
  class community_news;
  class main_window;
  class qt_application;
  class qt_interpreter_events;
  class release_notes;

  //! This class is a simple wrapper around QApplication so that we can
  //! reimplement QApplication::notify.  The octave_qapplication object
  //! should behave identically to a QApplication object except that it
  //! overrides the notify method so we can handle forward Octave
  //! execution_exception exceptions from the GUI thread to the
  //! interpreter thread.

  class octave_qapplication : public QApplication
  {
    Q_OBJECT

  public:

    octave_qapplication (int& argc, char **argv)
      : QApplication (argc, argv)
    { }

    virtual bool notify (QObject *receiver, QEvent *e) override;

    ~octave_qapplication (void) { };

  signals:

    void interpreter_event (const fcn_callback& fcn);
    void interpreter_event (const meth_callback& meth);
  };

  //! Container for windows that may be created from the command line or
  //! docked with the main GUI window.  Any of these windows that are
  //! created in command line mode will be adopted by the main window if
  //! it is opened from the command line.  Any that are undocked from
  //! the main window will remain open if control returns to the command
  //! line.

  class base_qobject;
  class documentation_dock_widget;
  class file_editor_interface;
  class files_dock_widget;
  class history_dock_widget;
  class terminal_dock_widget;
  class variable_editor;
  class workspace_model;
  class workspace_view;

  //! Base class for Octave interfaces that use Qt.  There are two
  //! classes derived from this one.  One provides a command-line
  //! interface that may use Qt graphics and another provides the
  //! full GUI experience.

  class base_qobject : public QObject
  {
    Q_OBJECT

  public:

    // Note: the GUI_APP argument is not needed with the new
    // experimental terminal widget.
    base_qobject (qt_application& app_context, bool gui_app = false);

    ~base_qobject (void);

    void config_translators (void);

    void start_main_thread (void);

    int exec (void);

    // The Octave application context.
    qt_application& app_context (void) { return m_app_context; }

    // The Qt QApplication.
    QApplication * qapplication (void) { return m_qapplication; };

    // Provided for convenience.  Will be removed once we eliminate the
    // old terminal widget.
    bool experimental_terminal_widget (void) const;

    // Provided for convenience.
    bool gui_running (void) const;

    bool have_terminal_window (void) const
    {
      return ! m_terminal_widget.isNull ();
    }

    main_window* get_main_window (void)
    {
      return m_main_window;
    }

    resource_manager& get_resource_manager (void)
    {
      return m_resource_manager;
    }

    shortcut_manager& get_shortcut_manager (void)
    {
      return m_shortcut_manager;
    }

    std::shared_ptr<qt_interpreter_events> get_qt_interpreter_events (void)
    {
      return m_qt_interpreter_events;
    }

    qt_interpreter_events * qt_link (void)
    {
      return m_qt_interpreter_events.get ();
    }

    interpreter_qobject * interpreter_qobj (void)
    {
      return m_interpreter_qobj;
    }

    workspace_model * get_workspace_model (void)
    {
      return m_workspace_model;
    }

    QPointer<terminal_dock_widget>
    terminal_widget (main_window *mw = nullptr);

    QPointer<documentation_dock_widget>
    documentation_widget (main_window *mw = nullptr);

    QPointer<files_dock_widget>
    file_browser_widget (main_window *mw = nullptr);

    QPointer<history_dock_widget>
    history_widget (main_window *mw = nullptr);

    QPointer<workspace_view>
    workspace_widget (main_window *mw = nullptr);

    // FIXME: The file_editor_interface needs to be a proper generic
    // interface for all editors (internal and external) for this to
    // work properly.
    QPointer<file_editor_interface>
    editor_widget (main_window *mw = nullptr);

    QPointer<variable_editor>
    variable_editor_widget (main_window *mw = nullptr);

    QPointer<community_news> community_news_widget (int serial = -1);

    QPointer<release_notes> release_notes_widget (void);

    QThread *main_thread (void) { return m_main_thread; }

    // Declared virtual so that a derived class may redefine this
    // method.

    virtual bool confirm_shutdown (void);

    template <typename T> void connect_interpreter_events (T *widget)
    {
      connect (widget, QOverload<const fcn_callback&>::of (&T::interpreter_event),
               this, QOverload<const fcn_callback&>::of (&base_qobject::interpreter_event));

      connect (widget, QOverload<const meth_callback&>::of (&T::interpreter_event),
               this, QOverload<const meth_callback&>::of (&base_qobject::interpreter_event));
    }

  public slots:

    void execute_command (const QString& command);

    // Note: START_GUI and CLOSE_GUI don't currently perform any work
    // with the old terminal widget.
    void start_gui (bool gui_app);
    void close_gui (void);

    void show_terminal_window (void);

    void show_documentation_window (const QString& file);

    void show_file_browser_window (void);

    void show_command_history_window (void);

    void show_workspace_window (void);

    void show_variable_editor_window (const QString& name,
                                      const octave_value& value);

    void handle_variable_editor_update (void);

    void show_community_news (int serial);

    void show_release_notes (void);

    void interpreter_ready (void);

    void interpreter_event (const fcn_callback& fcn);

    void interpreter_event (const meth_callback& meth);

    void interpreter_interrupt (void);

    // Note: these currently only work with the new experimental
    // terminal widget.
    void interpreter_pause (void);
    void interpreter_stop (void);
    void interpreter_resume (void);

    void copy_image_to_clipboard (const QString& file, bool remove_file);

  protected:

    qt_application& m_app_context;

    // Use these to ensure that argc and argv exist for as long as the
    // QApplication object.

    int m_argc;
    char **m_argv;

    octave_qapplication *m_qapplication;

    resource_manager m_resource_manager;

    shortcut_manager m_shortcut_manager;

    QTranslator *m_qt_tr;
    QTranslator *m_gui_tr;
    QTranslator *m_qsci_tr;

    bool m_translators_installed;

    std::shared_ptr<qt_interpreter_events> m_qt_interpreter_events;

    interpreter_qobject *m_interpreter_qobj;

    QThread *m_main_thread;

    bool m_gui_app;

    bool m_interpreter_ready;

    workspace_model *m_workspace_model;

    // Dock widgets that may be used from the command line.  They are
    // adopted by the desktop (main window) if it is also started from
    // the command line.

    QPointer<terminal_dock_widget> m_terminal_widget;

    QPointer<documentation_dock_widget> m_documentation_widget;

    QPointer<files_dock_widget> m_file_browser_widget;

    QPointer<history_dock_widget> m_history_widget;

    QPointer<workspace_view> m_workspace_widget;

    QPointer<file_editor_interface> m_editor_widget;

    QPointer<variable_editor> m_variable_editor_widget;

    QPointer<community_news> m_community_news;

    QPointer<release_notes> m_release_notes;

    main_window *m_main_window;
  };
}

#endif
